A protocol data unit (hereinafter referred to as PDU) used for transmitting information in a media access control (hereinafter referred to as MAC) layer generally includes a header and a payload.
The header of the PDU includes a connection identifier CID, which is an identification number for connection between a base station and a terminal. Generally, the connection identifier has a fixed length of 16 bits. Transmitting and receiving the connection identifier may cause overhead of a communication system.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.